The invention relates first of all to a hydraulic apparatus, for example for pressing or cutting workpieces, with a mounting head for tools which can be moved against one another.
An apparatus of this kind is known, for example, from German Patent Application 198 25 160, which corresponds to U.S. application. Ser. No. 09/319,908, Aug. 10, 1999. The content of this patent application is hereby incorporated as to its full content into the disclosure of the present invention.
With regard to the prior art described above, one technical problem for the invention is seen in improving the construction of a hydraulic apparatus of the type under discussion, particularly as regards its technical functioning.
This problem is solved first and foremost by the fact that the tools can be arranged in the mounting head in a manner laterally offset from one another in order, in the case of cutting tools, to allow them to move past one another. As a result of th is configuration, there is provided increased utility value for the hydraulic apparatus, especially when using cutting tools. In the case of a cutting operation, a movable cutting tool is displaced at least until its cutting edge moves behind the cutting edge associated with the fixed tool. This makes it possible to cut workpieces, such as solid or hollow sectional bars, to length cleanly and without burrs. The fact that the cutting tools can be moved past one another leads to a shearing division of the workpiece. The laterally offset arrangement of the tools relative to one another in the mounting head is furthermore also conceivable in the case of tools for pressing workpieces. The arrangement chosen also makes it possible to insert in the mounting head tools for other non-cutting operations on workpieces, bending tools for example. In a first embodiment, the tools are guided in grooves formed next to one another. In this regard, it is possible for a groove to be associated with each tool. However, it is furthermore also conceivable, given the formation of two grooves arranged next to one another, to associate these two tools in such a way that they are guided in common grooves formed beside one another. As a further embodiment of the subject matter of the invention, it is provided that the tools are guided in a common groove with additional support on opposite outer surfaces of groove walls. Irrespective of the number of grooves, they run in the direction of displacement of the tool or tools in the mounting head. Where the tools are arranged in a common groove, each tool preferably also engages over the associated groove wall bounding the groove to provide additional support against the outer surface of the groove wall. Metaphorically speaking, the construction is chosen in such a way that the workpiece, the groove and the groove wall of the mounting head forms a guide rail for the tool in the form of a tongue. Provision is furthermore made for grooves or guide structures for the tools to extend in the direction of displacement and to be provided on both sides of the tools, in order to provide tilt-free guidance of the tools. Where the tools are arranged in a common groove, the tool section sliding in the groove preferably corresponds to no more than half the width of the groove, so that both tools may be moved fully past one another. In another embodiment, it may be provided that the tools are guided in a common groove and interpenetrate one another. Accordingly, the tools are shaped in such a way that in particular the operative regions of the tools, for example the cutting edges of cutting tools, can enter into the region of the other tool. Thus, for example, provision is made for the tools to have guiding sections in the form of tongues for guidance in the common groove only in the end regions which are directed away from each other. These guiding sections extend over the entire width of the groove, whereas the actual operative region preferably corresponds to half the width of the groove, to allow the operative regions of the tools to move past one another. In an advantageous development of the subject matter of the invention, it is provided that the mounting head is formed as a closable rectangular guide. In this way, on the one hand, insertion of the various tools is facilitated, and, on the other hand, by means of the opened rectangular guide, the apparatus can be placed against the workpiece to be pressed or cut. This is of advantage, particularly in the case of very long workpieces or those in locations to which it is difficult to gain access. After it has been placed against them, the mounting head formed as a rectangular guide is closed, after which, as a further feature of the subject matter of the invention, the displaceable tool is acted upon in the rearward direction by a ram which can be actuated by means of the hydraulic apparatus. After the rectangular guide is closed, the direction of displacement of the movable tool runs in extension of the direction of displacement of the ram. The movement concerned is preferably a linear displacement of the ram and of the displaceable tool towards a fixed tool. Where the mounting head is formed as a rectangular guide, the longer side of the rectangle is aligned in the direction of displacement, at least in the closed position of the mounting head. A quadratic shape of the mounting head when viewed transversely to the direction of displacement of the tools is furthermore also conceivable. It is also possible to conceive of arrangements of the mounting head in which the displacement of the tools is effected in a nonlinear manner, for example in the form of a cam-guided displacement. In the preferred configuration of the mounting head as a rectangular guide, provision is made for the rectangular guide to be of three-piece construction, one piece being provided as an angled piece which encloses one longitudinal side, one piece being provided as a narrow-side piece and one piece being provided as a longitudinal-side piece. In this regard, it is furthermore preferred for the narrow-side piece to provide joints at each of its ends for the angled piece and for the longitudinal-side piece. It is proposed here that the narrow-side piece be provided in the region that can be associated with the apparatus. The narrow-side piece can furthermore be provided in the form of two lug-like plates which enclose end regions of the angled piece and of the longitudinal-side piece between them, the ram which can be moved by the hydraulic apparatus entering the guide space of the mounting head in the intermediate space provided between these plates. As a development of the subject matter of the invention, provision is made for the angled piece to provide a portion of a longitudinal side which overlaps with the longitudinal-side piece. As a consequence of this, the angled piece is formed to be substantially U-shaped in a side view transverse to the direction of displacement, with one U limb forming a longitudinal side which is arranged to be shorter than the other U limb, the free end of the other U-limb being provided with a bearing feature to allow pivoting displacement of the angled piece in the region of the narrow-side piece. In the closed position of the mounting head or rectangular guide, the shorter U limb coincides with the longitudinal-side piece, which is likewise mounted in a pivoting manner on the narrow-side piece, this position preferably furthermore being secured by positive locking. Thus, for example, one longitudinal side of the angled piece can have an upper projection which is provided with an undercut and enters into a correspondingly formed groove in the longitudinal-side piece. The piecesxe2x80x94angled piece and longitudinal-side piecexe2x80x94which are subject to spring-loading in the opening direction, are held in the closed position by the selected undercut. This position can only be released by deliberate action. To fix the tools in the mounting head, securing means for securing a tool in the mounting head are provided, in each case opposite one another, on the narrow-side piece of the mounting head. A configuration is preferred here in which a securing means is provided on the ram side for the tool to be acted upon by the ram and thus displaced, and a further fixing means for a fixed tool is, on the other hand, provided in the region of the U-limb of the angled piece which simultaneously forms a narrow-side piece. A configuration which is preferred here is one in which the securing means is formed as a positive locking pin which can be displaced transversely to the direction of motion of the tools. This is furthermore preferably in the form of a pin which has zones of reduced diameter in a longitudinal direction and is biassed by a spring in the direction of positive-locking engagement. Provision can furthermore be made for this positive-locking pin to be formed and arranged in such a way that by using it, there can be effected both fixing of the associatable tool to one or the other side of the narrow-side piece or of the ram and, furthermore, fixing of it on both sides at the same time.
The invention furthermore relates to a hydraulic apparatus, for example for pressing or cutting workpieces for instance, with a mounting head for tools which can be moved against one another, both cutting and pressing tools being disposable in the mounting head. As an advantageous development of the subject matter of the invention, it is proposed here that force-dependent control of the apparatus is effected both during a cutting operation and during a pressing operation. As a consequence of this, its operation is not dependent on the drive path of the ram or of the tool that can be displaced by the ram. As a consequence, various tools with various displacements can be inserted and used in an extremely simple manner.
The invention furthermore relates to a tool or adaptor for receiving a tool for securing in a mounting head. For advantageous development of a tool or adaptor of this kind, a fork-shaped mounting lug projecting in the direction of displacement is here proposed which has an enlarged retaining opening starting from a smaller insertion opening. This retaining opening, which preferably cooperates with a positive-locking pin of the mounting head, serves to fix the tool in the mounting head, thus for example to locate the tool on the mounting head as a fixed tool or to locate a tool on a ram projecting into the mounting head to form a displaceable tool. The positive-locking pin cooperating with the mounting lug has a region of reduced cross section in the longitudinal direction of the pin, the diameter of which corresponds approximately to that of the smaller insertion opening of the mounting lug. To fix the workpiece, the positive-locking pin is displaced in such a way that the region of reduced cross section can be traversed by the smaller insertion opening of the mounting lug for final entry of the positive-locking pin into the enlarged retaining opening. The positive-locking pin is displaced back into the original position, preferably with spring assistance, positive engagement being effected between the pin area of enlarged cross section and the enlarged retaining opening. As a further embodiment of the subject matter of the invention, provision is made for the mounting lug to be arranged relative to the tool or to the adaptor so as to project transversely to the direction of displacement. As a result of this, there is provided increased width of the mounting lug. In this regard, the mounting lug can be provided as a separate part which is, for example, rivetted to the tool. As an alternative, the construction can also be chosen in such a way that the mounting lug is formed to be aligned with the outer surface of the tool or of the adaptor. According to this, it is preferred that the mounting lug be formed integrally with the tool. The tool and the adaptor have means for guiding them in the mounting head. In regard to a plan view of these guide means, the mounting lug preferably extends to the side of the guide means and with a parallel offset relative to the means. It is furthermore proposed that two oppositely-located mounting lugs be provided. According to this, the tools grip over the associated sections of the mounting head in the region of their mounting lugs. As regards the guide structures, it is proposed that the tool or the adaptor have one or, optionally, two tongues located beside one another and extending in the direction of displacement of the tool or of the adaptor, these tongues resting in one or, if appropriate, two mutually adjacent grooves in the mounting head to form a tongue-and-groove arrangement. As a development of the subject matter of the invention, provision is made for the tool or the adaptor to have a tool working width which is less than the tongue width. Thus, for example, the tool working width can correspond approximately to half the tongue width, and it is furthermore preferred that the working section of the tool be aligned on one side with a tongue outer surface and thus extend approximately as far as the center of the tongue in the width direction. As an alternative, the arrangement can also be chosen in such a way that the tool working width is adapted to approximately correspond to the tongue width. It is furthermore proposed that the tongue extend over only part of the length of the tool or of the adaptor, for example over half the length of the tool as viewed in the direction of displacement of the tool. Provision can furthermore be made for the adaptor to have a projecting shoulder on both sides of the tongue. The tool accordingly has a total width which extends beyond the width of the tongue and the tool is thus supported in the mounting head in the region of the projecting shoulder on the groove flanks, which receive the tongue between them. As an alternative, it is also possible for the side face of the adaptor to be aligned with the side face of the tongue. The adaptor according to the invention is furthermore formed in such a way that it allows conventional pressing toolsxe2x80x94pressing jawsxe2x80x94to be inserted. Thus, for example, positive-locking openings can be provided for the purpose of fixing the tool on the adaptor. This can be for example a kind of catch coupling. A tongue-and-groove connection between tool and adaptor is furthermore also conceivable, the alignment of this groove and tongue preferably being transverse to the direction of displacement. The tool can furthermore be held in the adaptor by latching means, which latching means can be displaced to release the tool only by deliberate action. As regards the fixing of the tool in the adaptor, combinations of the configurations described above can also be used. In this regard, it is furthermore proposed that the securing lug be provided on the tool and that the securing lug engage over the adaptor. The adaptor itself is accordingly not provided with securing lugs and thus serves purely as a guide means in the mounting head. The tool provided with the securing lug, preferably two securing lugs, grips over the adaptor to give positive-locking engagement with the securing means of the mounting head. The tool according to the invention or the tool held by means of the adaptor preferably acts within the mounting head of the apparatus, i.e. the tool working regions, such as cutting edges or pressing jaws, act within the mounting head. As an alternative, however, provision is also made for the tools or tool working regions to operate outside the mounting head, thus for example in the form of a tool of the bolt-cutter type. Here, the only tool members which are displaced within the mounting head are those whose displacement is transmitted for example by a lever arrangement, to cutting or pressing jaws arranged offset relative to the mounting head. Such a configuration can furthermore also be used for punching, for example punching sheet metal. As a consequence, operations may in this way also be performed in a targeted manner without having to open the mounting head, particularly in the case of relatively long workpieces, in order to grasp the workpieces.
The invention furthermore relates to a pair of tools for insertion in a mounting head of a hydraulic apparatus. Here, an advantageous development of the pair of tools according to the invention is provided by cut-outs formed identically in both tools and corresponding to a profile cross section. Such a pair of tools is used, for example, for cutting to length profile stock pieces made, for example, of plastics or aluminium, the cut-outs in the two tools being provided to correspond to the profile cross section of the stock to be cut. In an initial position of the apparatus holding the pair of tools, the cut-outs coincide. The profile stock is then pushed through these as far as the desired position. When the apparatus is actuated, the tools, which are aligned in side by side disposition, are moved past one another, resulting in shearing of the profile stock. Owing to the fact that the cut-outs of the tools are shaped to correspond to the profile cross section, the cutting operation takes place without permanent deformation of the workpiece. Another advantageous configuration is provided by cutting edges formed on end faces, the end faces being opposite one another in the direction of displacement, and the cutting edges extending in a curved manner in the direction of displacement. Cutting edges which extend in a concave manner relative to the respective end face of a tool are preferred here, so that concentric cutting from the outside towards the center is effected, particularly in the case of workpieces which are circular in cross section. Externally threaded sections which adjoin the cutting edges laterally and are aligned transversely to the direction of displacement furthermore allow threaded rods to be cut to length. For this purpose, the tools are provided with semicircular recesses which are open towards the opposite end faces and have an external thread extending in the transverse direction of the tool. To counteract skewing of the workpiece, e.g. a threaded rod, provision is made for one tool to have a shell-shaped support on the side facing away from the cutting edge, the shell being located at a spacing from and coaxial with the externally threaded section. The support arrangement is preferably effected on the movable tool, a supporting shell which is in the form of a half shell in plan view being chosen. In this arrangement, the shell is aligned counter to the associated externally threaded section, with the radii being substantially the same.
The invention furthermore relates to a tool for securing in a mounting head of a hydraulic apparatus. In this regard, a receiving member to be secured in the mounting head and a working part situated outside the mounting head, such as a cutting jaw or a hole punch, are proposed for the purpose of achieving a technically functional improvement of the subject matter according to the invention. By virtue of this configuration, operations to be carried out by means of the hydraulic apparatus can also be performed outside the region of the mounting head, and linear movements, in particular, can be transmitted in various ways to the working part by the receiving member on the mounting side. Thus, provision is made for the receiving member to comprise a fixed part and a moving part. The displacement of a ram or piston brought about by means of the apparatus leads to the moving part being taken along in the manner already described in the case of the tools or adaptors with tools acting within the mounting head. In a configuration used by way of example, provision can be made for the moving part to be formed as a piston cooperating with a quantity of hydraulic fluid in the fixed part. As an alternative, provision can be made for the moving part to act directly or indirectly by way of linkages on a hydraulic piston. The moving part can furthermore also act on the working part directly or indirectly by way of links or the like. It is furthermore proposed that the tool is a shears-type tool, thus for example a bolt cutter. Thus, provision is made for the fixed part to be connected to a fixed jaw of the shears-type tool. Another proposal in this regard is that the moving part be connected to a pivoting jaw of the shears-type tool. According to the invention, a preferred linear displacement of the moving part accordingly leads by way of appropriately embodied and arranged links/levers to a pivoting displacement of the pivoting jaw relative to the fixed jaw. As an alternative, provision can be made for the tool to be a hole punch. A device of this kind is known from DE-A1 196 49 932. The content of this patent application is incorporated into the disclosure of the present invention, also for the purpose of including features of this patent application in claims of the present invention. It is additionally proposed that the moving part be formed as a cylinder accommodated in the cylinder-like fixed part, thus for example a hydraulic piston.
Finally, the invention relates to a method for cutting by means of a hydraulic apparatus in which tools which can be moved against one another are accommodated in a mounting head. To obtain an improved development of such a method, it is proposed here that, as regards the cutting edges, the tools should be guided past one another in the course of a cutting operation. The guidance of the tools past one another is preferably effected until they reach a position in whichxe2x80x94viewed in the direction of displacement, the cutting edge on one tool lies behind the cutting edge of the other tool.